Process for manufacturing artificial textile fibers from casein



" PatentedJan; 11,1944

' UNITED STATE PATENT" forloat 1.338.911

PROCESS FOR MANUFACTURING OIAL TEXTILE FIBERS FROM CASEIN Antonio renew, Milan, may; vested in Allen Property Custodian I application February 17,

the

Q 18 1938, Serial No'."191,m. Divided and this appllcation April 20, 1940,,Serial N0. 330,727.. In

ItalyMarcli 2, 1937 8 Claims.

' .agulating the same in acid baths (2) hardening the coagulatedfilaments by passing them through baths containing soluble salts at a temperature above 25 C. (twenty-five) and about 40' C. and (3) cutting the hardened filaments to the desired length and then insolubilising the fibers at a temperature above 25 C. and about 70 C. in baths of formaldehyde to which soluble salts have been added. 7 Specifically, the invention includes (1) spinning filaments from a solution of animal casein and coagulating 1 the same in acid baths (2) 2. hardening the filaments by passing the same firstly through a bath of sodium chloride at-a temperature above 25 C. and about 40 C. and then through a bath containing aluminium salts and sodium chloride at a temperature above 25 '30 C. and about 55 C, and (3) cutting the hardened filaments to the desired length and insolubilising the fibers at a temperature. above 25 C. and about 70 C. in baths of formaldehyde. to which soluble salts have been added. 'i Furthermore the invention includes (1). spinning'iilaments from.,a solution of casein, coagulating the same, in acid baths, insolubilising the same 'at low temperatures and (2) treatingthe filaments insolubilised at low temperatures with solutions of formaldehyde at a temperature above 25 C. and about 70 C. to render the same boil- 'ing-proof. 1

This application is a division of copendin previously filed parent application Serial "No. 191,000, filed February 17, 1038; said parent application, and therefore the present application, being based upon the earlier filing of corresponding application in Italy on March 2, 1937, which ltalianapplicationhas subsequently resulted in 7 Italian Patent No. 367,405, granted January 24',

1939.- a The invention will be now explained with reference to the example of carrying out into practice. J I

(01. 1H4) I e In the manufacture of fibers of casein in which an initial immersing bath for the filaments is provided, said immersion bath for the filaments being composed'of sodium chloride or other salts.

and-a preparatory bath for rendering the fibers insoluble or a complete bath for rendering the fiber insoluble it is of great importance that the baths temperature be not below C. The

temperature must be preferablybetween C.' and 40 C. for the first bath bf-sodium chloride or other. salts and between C; and. C. for

' the preparatory bath for renderingthe fibers insoluble, of aluminium salts, sodium chloride or for the complete bath for rendering the fibers insoluble of formaldehyde, aluminium salts and sodium chloride or other salts. It is also important that the temperature in the bath, in which. the fibers as soon as cut are introduced be not below 25 C., it being preferable to employ a temperature between the range 35 C. to 40 C. Y

The treatment for rendering the casein fibers insoluble extends over a very long period, even several days. when carried out in a bath at ambient temperature, which isusually less than 25 C., nevertheless the fibers ofler' little resistance to boiling extending over a long period. On the contrary, it is found that when the temperature J at that temperature completely resists boilin which. may extend over many hours. 'Before proceeding to this strong treatment it is preferableto pass the fibers for some hours into the collecting bathof the cut fibers at atemperature of between35 C. and 40 C;

Complete resistance to the extensive boiling ,could also be obtained, when the casein fibers which have been rendered insoluble at a temperature which-is lower than that indicated, for.

instance at 25 'Cjto 50 C., are treated, preferably after being washed and dried, with an aqueous solution of'formaldehyde at a temperature of about60 C. to C. for several hours, for

I example, five'hours. In this case, the addition of,

H the aluminium salts, of sodium chloride or of other soluble alkaline metal salts or earthy alka lies, to the formaldehyde solution, is unnecessary. This treatment could be effected with the dried casein fibers at any desired time, that is to say, even after a period of many months or years from the manufacturing date of the fiber has elapsed. Above all, itis of great importance that the treatment for rendering the fibers insoluble should be eiiected at temperatures .which. are not below 25 C., and that, when a temperature above 25 C., is applied, the relative operation should take place in an autoclave (digester) which 5 should preferably be rotary, so" as{ to maintain the fibers in motion while at the same time, the

bath for rendering the fibers insoluble is made to v circulate in the interior of the autoclave.

The further particulars of the-man-ufacturing process for the textile fibers ,of' casein may be modified in various ways without departing from the spirit of the invention.

The invention can also be applied to the'man ufactur'e of mixed fibers of casein and cellulose.

01 course the invention also covers the textile fibers of casein obtained by the indicated proc-' ess.

. Having now particularly described and ascertained the nature of my said invention and in 2 what manner the same is to be performed I declare that what I claim is:

1. In a process for the manufacture of artificial text- 1e fibers from casein and following the stage of spinning a multiplicity of filaments from an alkaline solution of thecasein and coagulating them in an acid coagulating bath; the steps of aftertreating the delicate coagulated filaments comprising initially hardening them in an aqueous bath containingat least one soluble aluini- 3 num salt, and then subjecting the hardened fila- -ments to the insolubilizing action of an aqueous formaldehyde bath maintained at a temperature between about and 70 0., thereby to render the resulting casein fibers proof against impairment under boilingtemperature,

2. The process as in claim 1 and wherein the initial hardening bath contains also sodium chloride and is maintained at a temperature be- 40 tween about 35 and 40 C,.

3. The process as in claim 1 and wherein following the initial hardening baththe filaments are treated in a second aluminum salt hardening bath, containing sodium chloride, and maintained at a temperature between about and 45 4. In a process for the manufacture of artifi cial textile fibers from casein and following the stage of spinning a multiplicityof filaments from an alkaline 'soltitionof' the casein and coagulating them in an acid coagulating bath; the steps of aitertreating the delicate coagulated filaments comprising hardening thein in an aqueous bath containing at* least one soluble 'alu'minuin salt, and then insolubilizing them in an aqueous formaldehyde bath maintained at a temperature betweenaboutr fio? and 570 C.

, 5." A process as in claim v4 and wherein the insolubilizing bath contains both a soluble aluminu'ni hardening salt and sodium chloride.

6: In aprocess for the manufacture of artifi-' and thereafter to a final insolubilizing bath of formaldehyde maintained at a temperature of about "60 to (3.. thereby to render the resultf ing casein fibers proof against impairment under boiling temperature. 3 I

7. The process as in claim 6 and wherein after the hardening bath the filaments are cut to length before treatment in the preliminary insolubilizing'bath. I

8. In a process for manufacturingartificial textile fibers from an alkaline solution of casein thefstep, following spinning .and acid coagula:

'tion. of the casein filaments, and precedingim solubilizing the filaments by formaldehyde, of treating the freshly coagulated filaments in at least one aqueous bath at a temperature of about 40 C. in which bath at least one salt-has been dissolved taken from the group consisting of water-soluble salts of alkaline metals and o alkaline earth metals.

I ANTONIO FERRE'I'II. 

